Because I really don't understand PACMiC ... they pay for 120 days how much (currently)?
Best explanation of PACMiC v2 I have come across is at this Bitmain Talk
thread. Expect to earn about $11 on a $290 investment:
Ok we've had this discussion before. I know because I'm the one who raised hell until I got the correct answer and here it is.
1 PACMICs is 1 THS of an S5. You own this 1 THS for as long as it takes to earn back the 1 BTC you invested and absolutely no longer.
There is no maintenance, so you earn the full 0.00961979 BTC for each day you have it.
This works out to about 103 days that you get to keep it.
After that 1 BTC is returned you are done, you get no more from the contract and it shuts off.
Now of course there are difficulty changes that will change your payout, when I bought mine it was 0.01 BTC daily.
Since no one would loan anyone 1 BTC only to be paid back 1 BTC over 100 days later, they give you an "interest" payment that they call a "profit".
You are paid a PROFIT of 0.45 satoshis per second for the entire duration of your contract.
This is interest and it works out to 0.0003888 BTC daily.
This amount is fixed, it is not tied to pool luck and it is not tied to difficulty level increases, although if the difficulty level does increase or the pool luck takes a crap, the number of days your contract would run increases,
so you get the same daily interest payment, but you get more days.
If the difficulty level stays the same and 103 days is the total run of the contract, then you are looking at a total PROFIT of 0.04 BTC.
If you assume that the $290 level holds, difficulty stays flat and pool luck is average,
that means an investment of $290 today becomes $301.61 at the end.
A PACMICs is a bet that
the pool rate will have bad luck and/or
that the difficulty level will continue to increase
or that bitcoins of the future will be worth substantially more than they are now
All of these events make your PACMICs position much more attractive.
Now here is where it can get confusing and this is where I ended up raising hell since I sold it to my business partners based on what they were saying at the time which was different than how it actually works...
Autorebuy!
You would think that with auto-rebuy turned on, that your principal would increase by 0.00961979 BTC daily.
This causes some awesome compounding effects and makes the math so very much more attractive.
In fact if this were the case you could easily turn 1 BTC into 3 BTC over a period of 180 days (assuming 80 days of availability for compounding).
Sorry, that's just not how this little system works.
Instead the 0.00961979 BTC is used to buy more hashing power. As soon as you turn auto-rebuy back off or it turns off automatically, then all of that hashing power is used to speed up the payback period.
Since your profit here is based on number of days that the contract runs, increasing the hashpower reduces the number of days until you get your coin back. This KILLS your profits, you have less days to collect your profits, i.e. less days of interest to collect.
To offset that a little, they do add the "interest" or "profit" directly to the principle so your principle increases at a rate of 0.0003888 BTC daily for each BTC invested for each day you have auto-rebuy on.
Let's do the same 180 days calc. 80 days of compounding and up to 100 days beyond that to payoff. At the end of 80 days you have ~3 THS of capacity that only needs to earn back 1.0311 BTC in principal.
You will have 1.05 BTC at the end of 6 months for each BTC invested, but the contract actually completed in about 120 days.
So the best way and only reason to consider buying a PACMICs is if you don't mind giving Bitmain a low interest loan for about 100 days. In exchange you have a little bit of a hedge against difficulty increases and bad pool luck.
Don't put substantial amounts into it, it's a bad deal all around.